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Stefanon, Mauro,Yan, Haojing,Mobasher, Bahram,Barro, Guillermo,Donley, Jennifer L.,Fontana, Adriano,Hemmati, Shoubaneh,Koekemoer, Anton M.,Lee, BoMee,Lee, Seong-Kook,Nayyeri, Hooshang,Peth, Michael,Pf Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.229 No.2
<P>We present a 0.4-8 mu m multi-wavelength photometric catalog in the Extended Groth Strip (EGS) field. This catalog is built on the Hubble Space Telescope (HST) WFC3 and ACS data from the Cosmic Assembly Nearinfrared Deep Extragalactic Legacy Survey (CANDELS), and it incorporates the existing HST data from the Allwavelength Extended Groth strip International Survey (AEGIS) and the 3D-HST program. The catalog is based on detections in the F160W band reaching a depth of F160W. =. 26.62 AB (90% completeness, point sources). It includes the photometry for 41,457 objects over an area of approximate to 206 arcmin(2) in the following bands: HST/ACS F606W and F814W; HST WFC3 F125W, F140W, and F160W; Canada-France-Hawaii Telescope (CFHT)/ Megacam u*, g', r', i' and z'; CFHT/WIRCAM J, H,. and KS; Mayall/NEWFIRM J1, J2, J3, H1, H2, and K; Spitzer IRAC 3.6, 4.5, 5.8, and 8.0 mu m. We are also releasing value-added catalogs that provide robust photometric redshifts and stellar mass measurements. The catalogs are publicly available through the CANDELS repository.</P>
Astrochemical Properties of Planck Cold Clumps
Tatematsu, Ken’ichi,Liu, Tie,Ohashi, Satoshi,Sanhueza, Patricio,Nguyê,̃,n Lu’o’, Quang,Hirota, Tomoya,Liu, Sheng-Yuan,Hirano, Naomi,Choi, Minho,Kang, Miju,A.Thompson, Mark,Fuller, Gary,Wu, Y Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.228 No.2
<P>We observed 13 Planck cold clumps with the James Clerk Maxwell Telescope/SCUBA-2 and with the Nobeyama 45 m radio telescope. The N2H+ distribution obtained with the Nobeyama telescope is quite similar to SCUBA-2 dust distribution. The 82 GHz HC3N, 82 GHz CCS, and 94 GHz CCS emission are often distributed differently with respect to the N2H+ emission. The CCS emission, which is known to be abundant in starless molecular cloud cores, is often very clumpy in the observed targets. We made deep single-pointing observations in DNC, (HNC)-C-13, N2D+, and cyclic-C3H2 toward nine clumps. The detection rate of N2D+ is 50%. Furthermore, we observed the NH3 emission toward 15 Planck cold clumps to estimate the kinetic temperature, and confirmed that most targets are cold (less than or similar to 20 K). In two of the starless clumps we observed, the CCS emission is distributed as it surrounds the N2H+ core (chemically evolved gas), which resembles the case of L1544, a prestellar core showing collapse. In addition, we detected both DNC and N2D+. These two clumps are most likely on the verge of star formation. We introduce the chemical evolution factor (CEF) for starless cores to describe the chemical evolutionary stage, and analyze the observed Planck cold clumps.</P>
A MODEL FOR THE DUST ENVELOPE OF THE SILICATE CARBON STAR IRAS 09425-6040
Published by the University of Chicago Press for t 2016 The Astrophysical journal Vol.819 No.1
<P>IRAS 09425-6040 (I09425) is a silicate carbon star with conspicuous crystalline silicate and water-ice features and emission excesses in the far-infrared and millimeter (mm) wavelength ranges. To understand properties of the dust envelope of I09425, we propose a physical model based on the observations and known properties of asymptotic giant branch stars and dust. We perform radiative transfer model calculations using multiple dust shells and disks with various dust species. We compare the model results with the observed spectral energy distribution (SED) acquired with different telescopes. We find that the physical model for I09425 using multiple shells of carbon and silicate dust and multiple disks of amorphous and crystalline silicates reproduces the observed SED fairly well. This object looks to have detached cold O-rich (silicate and water-ice) dust shells, which could be remnants of the recent chemical transition from O to C and an inner C-rich dust shell. A long-lived thin disk of very large silicate grains can reproduce the emission excess in the mm wavelength band and a recently formed thick disk of crystalline silicates can reproduce the prominent emission features in the spectral range 8-45 mu m. The highly crystallized silicates could be recently formed by high temperature annealing due to the last O-rich superwind just before the chemical transition of the central star. I09425 could be a rare object that has the remnants of past O-rich stellar winds in the outer shells as well as in the circumbinary disks.</P>
Lee, Jeong Ae,Sohn, Bong Won,Jung, Taehyun,Byun, Do-Young,Lee, Jee Won Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.228 No.2
<P>We present the catalog of the KVN Calibrator Survey (KVNCS). This first part of the KVNCS is a single-dish radio survey simultaneously conducted at 22 (K band) and 43 GHz (Q band) using the Korean VLBI Network (KVN) from 2009 to 2011. A total of 2045 sources are selected from the VLBA Calibrator Survey with an extrapolated flux density limit of 100 mJy at the K. band. The KVNCS contains 1533 sources in the K band with a flux density limit of 70 mJy and 553 sources in the Q band with a flux density limit of 120 mJy; it covers the whole sky down to -32 degrees 5 in decl. We detected 513 sources simultaneously in the K and Q bands; similar to 76% of them are flatspectrum sources (-0.5 <= alpha <= 0.5). From the flux-flux relationship, we anticipated that most of the radiation of many of the sources comes from the compact components. The sources listed in the KVNCS therefore are strong candidates for high-frequency VLBI calibrators.</P>
First Near-infrared Imaging Polarimetry of Young Stellar Objects in the Circinus Molecular Cloud
Kwon, Jungmi,Nakagawa, Takao,Tamura, Motohide,Hough, James H.,Choi, Minho,Kandori, Ryo,Nagata, Tetsuya,Kang, Miju Published by the University of Chicago Press for t 2018 The Astrophysical journal Supplement series Vol.234 No.2
<P>We present the results of near-infrared (NIR) linear imaging polarimetry in the J, H, and K-s bands of the low-mass star cluster-forming region in the Circinus Molecular Cloud Complex. Using aperture polarimetry of point-like sources, positive detection of 314, 421, and 164 sources in the J, H, and Ks bands, respectively, was determined from among 749 sources whose photometric magnitudes were measured. For the source classification of the 133 point-like sources whose polarization could be measured in all 3 bands, a color-color diagram was used. While most of the NIR polarizations of point-like sources are well-aligned and can be explained by dichroic polarization produced by aligned interstellar dust grains in the cloud, 123 highly polarized sources have also been identified with some criteria. The projected direction on the sky of the magnetic field in the Cir-MMS region is indicated by the mean polarization position angles (70 degrees) of the point-like sources in the observed region, corresponding to approximately 1.6 x 1.6 pc(2). In addition, the magnetic field direction is compared with the outflow orientations associated with Infrared Astronomy Satellite sources, in which two sources were found to be aligned with each other and one source was not. We also show prominent polarization nebulosities over the Cir-MMS region for the first time. Our polarization data have revealed one clear infrared reflection nebula (IRN) and several candidate IRNe in the Cir-MMS field. In addition, the illuminating sources of the IRNe are identified with near-and mid-infrared sources.</P>
Liu, Tie,Kim, Kee-Tae,Juvela, Mika,Wang, Ke,Tatematsu, Ken’ichi,Francesco, James Di,Liu, Sheng-Yuan,Wu, Yuefang,Thompson, Mark,Fuller, Gary,Eden, David,Li, Di,Ristorcelli, I.,Kang, Sung-ju,Lin, Yuxin Published by the University of Chicago Press for t 2018 The Astrophysical journal Supplement series Vol.234 No.2
<P>The low dust temperatures (< 14 K) of Planck Galactic cold clumps (PGCCs) make them ideal targets to probe the initial conditions and very early phase of star formation. 'TOP-SCOPE' is a joint survey program targeting similar to 2000 PGCCs in J = 1-0 transitions of CO isotopologues and similar to 1000 PGCCs in 850 mu m continuum emission. The objective of the 'TOP-SCOPE' survey and the joint surveys (SMT 10 m, KVN 21 m, and NRO 45 m) is to statistically study the initial conditions occurring during star formation and the evolution of molecular clouds, across a wide range of environments. The observations, data analysis, and example science cases for these surveys are introduced with an exemplar source, PGCC G26.53+0.17 (G26), which is a filamentary infrared dark cloud (IRDC). The total mass, length, and mean line mass (M/L) of the G26 filament are similar to 6200 M-circle dot, similar to 12 pc, and similar to 500 M-circle dot pc(-1), respectively. Ten massive clumps, including eight starless ones, are found along the filament. The most massive clump as a whole may still be in global collapse, while its denser part seems to be undergoing expansion owing to outflow feedback. The fragmentation in the G26 filament from cloud scale to clump scale is in agreement with gravitational fragmentation of an isothermal, nonmagnetized, and turbulent supported cylinder. A bimodal behavior in dust emissivity spectral index (beta) distribution is found in G26, suggesting grain growth along the filament. The G26 filament may be formed owing to large-scale compression flows evidenced by the temperature and velocity gradients across its natal cloud.</P>
Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei
Kim, Minjin,Ho, Luis C.,Peng, Chien Y.,Barth, Aaron J.,Im, Myungshin Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.232 No.2
<P>We present detailed image analysis of rest-frame optical images of 235 low-redshift (z less than or similar to 0.35) Type 1 active galactic nuclei (AGNs) observed with the Hubble Space Telescope. The high-resolution images enable us to perform rigorous two-dimensional image modeling to decouple the luminous central point source from the host galaxy, which, when warranted, is further decomposed into its principal structural components (bulge, bar, and disk). In many cases, care must be taken to account for structural complexities such as spiral arms, tidal features, and overlapping or interacting companion galaxies. We employ Fourier modes to characterize the degree of asymmetry of the light distribution of the stars as a quantitative measure of morphological distortion due to interactions or mergers. We examine the dependence of the physical parameters of the host galaxies on the properties of the AGNs, namely, radio-loudness and the width of the broad emission lines. In accordance with previous studies, narrow-line (H beta FWHM <= 2000 km s(-1)) Type 1 AGNs, in contrast to their broad-line (H beta FWHM > 2000 km s(-1)) counterparts, are preferentially hosted in later-type, lower-luminosity galaxies, which have a higher incidence of pseudo-bulges, are more frequently barred, and are less morphologically disturbed. This suggests that narrow-line Type 1 AGNs experienced a more quiescent evolutionary history driven primarily by internal secular evolution instead of external dynamical perturbations. The fraction of AGN hosts showing merger signatures is larger for more luminous sources. Radio-loud AGNs generally preferentially live in earlier-type (bulge-dominated), more massive hosts, although a minority of them appear to contain a significant disk component. We do not find convincing evidence for enhanced merger signatures in the radio-loud population.</P>
The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 ≤ <i>z</i> ≤ 5.4
Jeon, Yiseul,Im, Myungshin,Kim, Dohyeong,Kim, Yongjung,Jun, Hyunsung David,Pak, Soojong,Taak, Yoon Chan,Baek, Giseon,Choi, Changsu,Choi, Nahyun,Hong, Jueun,Hyun, Minhee,Ji, Tae-Geun,Karouzos, Marios,K Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.231 No.2
<P>We present the first results of our survey for high-redshift quasars at 5 less than or similar to z less than or similar to 5.7. The search for quasars in this redshift range has been known to be challenging due to the limitations of the filter sets used in previous studies. We conducted a quasar survey for two specific redshift ranges, 4.60 <= z <= 5.40 and 5.50 <= z <= 6.05, using multi-wavelength data that include observations made with custom-designed filters, is and iz. Using these filters and a new selection technique, we were able to reduce the fraction of interlopers. Through optical spectroscopy, we confirmed six quasars at 4.7 <= z <= 5.4 with -27.4 < M-1450 < -26.4 that recently were discovered independently by another group. We estimated black hole masses and Eddington ratios of four of these quasars from optical and near-infrared spectra, and found that these quasars are undergoing nearly Eddington-limited accretion that is consistent with the rapid growth of supermassive black holes in luminous quasars at z similar to 5.</P>
Abbott, B. P.,Abbott, R.,Abbott, T. D.,Abernathy, M. R.,Acernese, F.,Ackley, K.,Adams, C.,Adams, T.,Addesso, P.,Adhikari, R. X.,Adya, V. B.,Affeldt, C.,Agathos, M.,Agatsuma, K.,Aggarwal, N.,Aguiar, O. Published by the University of Chicago Press for t 2017 The Astrophysical journal Vol.841 No.2
<P>We present the results of the search for gravitational waves (GWs) associated with gamma-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 gamma-ray bursts for which LIGO data are available with sufficient duration. For all gamma-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of 10(-2)M(circle dot)c(2). were emitted within the 16-500 Hz band, and we find a median 90% confidence limit of 71 Mpc at 150 Hz. For the subset of 19 short/hard gamma-ray bursts, we place lower bounds on distance with a median 90% confidence limit of 90 Mpc for binary neutron star (BNS) coalescences, and 150 and 139 Mpc for neutron star-black hole coalescences with spins aligned to the orbital angular momentum and in a generic configuration, respectively. These are the highest distance limits ever achieved by GW searches. We also discuss in detail the results of the search for GWs associated with GRB 150906B, an event that was localized by the InterPlanetary Network near the local galaxy NGC 3313, which is at a luminosity distance of 54 Mpc (z = 0.0124). Assuming the gamma-ray emission is beamed with a jet half-opening angle <= 30 degrees, we exclude a BNS and a neutron star-black hole in NGC 3313 as the progenitor of this event with confidence > 99%. Further, we exclude such progenitors up to a distance of 102 Mpc and 170 Mpc, respectively.</P>